In essence, material possessions or wealth (9)
I believe the answer is:
substance
This clue is a quadruple definition!!
'in essence' is the first definition.
'substance' can be an answer for 'essence' (synonyms). I'm unsure of the 'in' bit.
'material' is the second definition.
(I've seen this before)
'possessions' is the third definition.
(thesaurus)
'or' is a link.
'wealth' is the fourth definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for substance that I've seen before include "Matter or material that a thing is made of" , "Property" , "Physical matter" , "Basic matter" , "wealth" .)